<template>
  <div class="home-page">
    <div class="banner">
      <div class="container">
        <h1 class="logo-font">conduit</h1>
        <p>A place to share your knowledge.</p>
      </div>
    </div>

    <div class="container page">
      <div class="row">
        <div class="col-md-9">
          <div class="feed-toggle">
            <ul class="nav nav-pills outline-active">
              <li v-if="user" class="nav-item">
                <nuxt-link
                  exact
                  class="nav-link"
                  :class="{ active: tab === 'your_feed'}"
                  :to="{ name: 'home', query: { tab: 'your_feed' }}"
                >
                  Your Feed
                </nuxt-link>
              </li>
              <li class="nav-item">
                <nuxt-link
                  exact
                  class="nav-link"
                  :class="{ active: tab === 'global_feed'}"
                  :to="{ name: 'home', query: { tab: 'global_feed' }}"
                >
                  Global Feed
                </nuxt-link>
              </li>
              <li v-if="tag" class="nav-item">
                 <nuxt-link
                  exact
                  class="nav-link"
                  :class="{ active: tab === 'tag'}"
                  :to="{ name: 'home', query: { tab: 'tag', tag: tag }}"
                >
                  # {{ tag }}
                </nuxt-link>
              </li>
            </ul>
          </div>

          <div class="article-preview" v-for="article in articles" :key="article.slug">
            <div class="article-meta">
              <nuxt-link
                :to="{
                  name: 'profile',
                  params: {
                    username: article.author.username
                  }
                }"
              >
                <img :src="article.author.image" />
              </nuxt-link>
              <div class="author">
                <nuxt-link
                  :to="{
                    name: 'profile',
                    params: {
                      username: article.author.username
                    }
                }"
                >{{ article.author.username }}</nuxt-link>
                <span class="date">{{ article.createAt | date('MMM DD, YYYY') }}</span>
              </div>
              <button
                class="btn btn-outline-primary btn-sm pull-xs-right"
                :class="{ active: article.favorited }"
                @click="onFavorite(article)"
                :disabled="article.favoriteDisabled"
              >
                <i class="ion-heart"></i>
                {{ article.favoritesCount }}
              </button>
            </div>
            <nuxt-link
              :to="{ name: 'article', params: { slug: article.slug } }"
              class="preview-link"
            >
              <h1>{{ article.title }}</h1>
              <p>{{ article.description }}</p>
              <span>Read more...</span>
            </nuxt-link>
          </div>

          <nav>
            <ul class="pagination">
              <li
                class="page-item"
                :class="{ active: page === item }"
                v-for="item in totalPage"
                :key="item"
              >
                <nuxt-link
                  class="page-link"
                  :to="{ name: 'home', query: { page: item, tag: $route.query.tag, tab: tab }}"
                >{{ item }}</nuxt-link>
              </li>
            </ul>
          </nav>
        </div>

        <div class="col-md-3">
          <div class="sidebar">
            <p>Popular Tags</p>

            <div class="tag-list">
              <nuxt-link
                v-for="item in tags"
                :key="item"
                :to="{ name: 'home', query: { tag: item, tab: 'tag' } }"
                class="tag-pill tag-default"
              >{{ item }}</nuxt-link>
            </div>
          </div>
        </div>
      </div>
    </div>
  </div>
</template>
<script>
import { getArticles, getYourFeedArticles, addFavorite, deleteFavorite } from "@/api/article";
import { getTags } from "@/api/tag";
import { mapState } from 'vuex';

export default {
  name: "HomePage",
  async asyncData({ query }) {
    const page = query.page - 0 || 1;
    const limit = 20;
    const tab = query.tab || "global_feed";
    const tag = query.tag;
    const loadArticles = tab === 'global_feed' ? getArticles : getYourFeedArticles;

    const [articleRes, tagRes] = await Promise.all([
      loadArticles({
        limit,
        offset: (page - 1) * limit,
        tag,
      }),
      getTags(),
    ]);

    const { articles, articlesCount } = articleRes.data;
    const { tags } = tagRes.data;

    articles.forEach(article => article.favoriteDisabled = false);

    return {
      articles,
      articlesCount,
      tags,
      limit,
      page,
      tab,
      tag,
    };
  },
  watchQuery: ["page", "tag", 'tab'],
  computed: {
    totalPage() {
      return Math.ceil(this.articlesCount / this.limit);
    },
    ...mapState(['user'])
  },
  methods: {
    async onFavorite(article) {
      article.favoriteDisabled = true;

      if (article.favorited) {
        await deleteFavorite(article.slug)
        article.favorited = false
        article.favoritesCount += -1
      } else {
        await addFavorite(article.slug)
        article.favorited = true
        article.favoritesCount += 1
      }

      article.favoriteDisabled = false;
    }
  }
};
</script>
<style>
</style>